1. Field of the Invention
The present invention relates to earth moving equipment, and in particular, to devices and methods for enabling such equipment to work with a variety of working accessories.
2. Description of Related Art
Some earth moving equipment are dedicated to a single purpose. For example, some (but not all) excavators or bulldozers are fitted with a bucket or dozer blade that is not easily replaced with a different type of working implement. Other equipment such as skid steer loaders are typically designed with adapters that can handle any one of a number of different working accessories. Potential accessories include augers, buckets, forklifts, grapplers, graders, spreaders, scarifiers, scrapers, tillers, etc.
Clark Equipment Co. (North Dakota) offers a Bob-Tach mounting system that allows an operator to quickly replace one type of working accessory with another type. This commercially available adapter has an upper edge designed to fit into a pocket of an working accessory, and a lower edge fitted with locking pins that can be pushed into complementary holes in a lower ledge of the accessory. In practice, the adapter is simply driven into a position to catch the pockets of the accessory, before being lifted, and then latched in place by manually operating levers that drive the locking pins into the accessory's holes.
Some compact excavators include a dozer blade mounted on a support structure that can articulate in order to lift/lower the dozer blade. The lifting/lowering of the blade is accomplished by a central hydraulic cylinder. In some cases the excavator's dozer blade is supported in bearing plates that allow the blade to swing azimuthally, and a side mounted hydraulic cylinder is used to effectuate this swinging.
A dozer blade mounted in this fashion is not readily replaced with another type of working accessory. Moreover, even if replacement were feasible, the native support structure does not provide the ability to adjust the pitch angle of the accessory, an adjustment that can be very important in many applications.
If the type of working accessory cannot be easily changed, then many dedicated pieces of earth moving equipment may be needed at a worksite. Some of the dedicated equipment may remain idle waiting for its turn. In some cases the various pieces of dedicated equipment may be scheduled to arrive on different days to avoid downtime, but this greatly extends the work schedule and delays the completion date.
See also U.S. Pat. Nos. 4,966,240; 4,464,852; 7,690,441; 8,700,271; and 8,024,875; as well as U. S. Patent Application Publication No. 2014/0317967.